Method of making coiled springs and spring casings



y- 1931. c. L. PAULUS ET AL 1,304,705

METHOD OF MAKI ING COILED SPRINGS AND SPRING CASINGS Filed April 18, 1922 13;! W I I @7079 Patented May 12, 1931 UNITED STATES- PATENT OFFICE CHARLES LEIGH PAULUS, 0F DAYTON, OHIO, AND HERBERT O. RUSSELL, OF DETROIT, MICHIGAN METHOD OF MAKING COILED SPRINGS AND SPRING CASINGS Application filed April 18,

This invention relates to a new' method of winding coiled springs, casings, and the like,

eliminating the usual heat treatment which has up to this time been found necessary in order to produce a spring or casing of the type referred to having the several coils or convolutions thereof closed or in actual contactual relation to each other.

The invention is particularly adapted to flexible casings such as are used in conjunction with an enclosed flexible cable similar to what is known as the Bowden wire control. A casing produced by the method hereinafter particularly described is superior to the ordinary flexible tubular casing in that when the cable and casing are performing their respective functions the casing is under actual compression while the cable or enclosed Wire is under tension.

With the above and other objects in View, the invention consists in the novel method herein fully described and claimed.

The accompanying drawing represents a coiled spring or casing, diagrammatically illustrating the novel method involved.

In the drawing, 1 designates a coiled spring, casing or the like, and 2 designates the rod or wire from'which the spring or casing is formed.

In the preferred manner of carrying out the invention, the rod or wire 2 is wound upon a standard spring arbor, in the same manner the springs are now wound. As the arbor is turned the wire to be coiled is drawn from a source of supply, and the straight incoming part c is continually forced laterally by the formed portion of the work in the direction indicated by arrow d. The lateral movement of the part 0 tends to set up an axial twist in its adjacent coiled part, indicated as a section of the coil lying between dotted lines a and b. This is what may be termed the normal twist of a coiled wire. In this illustration the normal twist is counterclockwise. To overcome this twist and to cause the adjacent convolutions of the formed coil to forcibly hug each other, the part c of the wire is given an axial twist in a clockwise direction, as indicated by the full line,

arrow in the drawing, such axial twistabeing 1922. Serial No. 555,412.

given to the wire or rod simultaneously with the winding of. the rod or wire around the arbor. This axial twist of the rod or wire 2 causes a natural tendency of the metal, which has been stressed an amount not to exceed the elastic limit of the metal, to untwist in the direction of the dotted arrow in the drawing, to assume its original condition so that each convolution hugs the next conv0- lution. In other words, where the rod or wire 2 is wound onto an arbor and twisted in the direction of the full line arrow in the drawing, each coil of the wire as it is coiled onto the arbor untwists slightly in the direction of the dotted arrow in the drawing, and in so doing moves into close relation with the next coil. This is a simple mechanical process. The twisting cant obviously exceed the elastic limit of the wire, or there will be no .der compression and which is nevertheless flexible. The spring casing snaps back or recoils when flexed and is not flabby as are springs or spring casings wound without the twist mentioned. This is a very desirable characteristic for use in Bowden casings. It will be observed that the result above described is obtained without the heat treatment heretofore found necessary in securing practical results. The improved product is superior to the old product due to the elimination of end play of the casing or easy separation between the convolutions thereof and furthermore the cost of production is materially reduced.

Instead of winding the wire or rod around a mandrel it may be forcibly fed into a'tubular die with an internal spiral or thread-like channel which the convolutions will readily follow. The wire or rod is twisted just before it enters such die.

Having thus described my invention, I claim:

1. In the art of making coiled springs, the herein described method, consisting in winding a rod or wire into a coil and simultaneously causing the convolutions of the coil to assume a closed contactual relation by imparting an axial twist to the rod or wire.

2. In the art of making coiled springs, the herein described method, consisting in winding a rod or wire into a coil and simultaneously causing the convolutions of the coil to assume a closed contactual relation by imparting an axial twist to the rod or wire in one direction so it tends to untwist in the other direction and in so doing causes each convolution to hug the next adjacent convolution.

3. In the art of making coiled springs, the herein described method, consisting in winding a rod or wire and simultaneously imparting an axial twist to the rod or wire to an extent within the elastic limits of the rod or wire to produce a close-wound spring with the convolutions in contactual relation.

4:. The process of making a coil by twisting a rod or wire an amount not to exceed the clastic limit thereof and in the direction opposite to the normal twist of the rod or wire.

In testimony whereof we have afiixed our signatures.

CHARLES LEIGH PAULUS. HERBERT O. RUSSELL. 

